Two-cycle gas engine



W. E. EWART Dec. 1 1925.

TWO CYCLE GAS ENGINE Filed March 5, 1923 //Vl E VTOR HTTORNEV 'Patented Dec. 1, 1925.

umreo STATES WILLIAM E. nwannor RAYMOND, WASHINGTON.

TWO-CYCLE -ens ENGINE.

l Application filed larch 5, 1923. Serial No. 822,814.

To all whom it may concern:

Be it known that I, WILLIAM .E. EWART, citizen of the United States, residing at Raymond, county of Pacific, and State of Washington, have invented a new and useful Two-Cycle Gas Engine; and 1 do hereby said declare that the following is a full, clear, and exact specification, such as will enable others skilledin the art to which it appertains to make and use the same.

The invention is an engine having a power cylinder, and a scavenger cylinder, with a sleevepiston so constructed as to form a smaller piston in said sleeve piston, same piston beingenlarged at one end, to form a arger piston for scavenger cylinder and a smaller piston to work within cylinder of piston.

The object of the invention is to get the maximum of power in a minimum of space and weight.

Another object of the invention is to provide a spark plug and means for operating it which may fire inside of a iston.

And anot or object of the invention is to provide an engine having three chambers on the same center line, two of which transmit power ifrom explosions to the crank shaft and the other a scavenger cylinder.

With these ,ends in view the invention embodies an engine having one piston inside of the sleeve an enlarge cylinder at the lower end'of the smaller; and a means for admitting, exploding and discharging gases to and from the smaller 0 linders.

Other eatures and advantages of the invention will ap ar from the followin description taken 1n connection with the awin? wherein lgure 1 1s a cross section on the center line of the engine showin the larger piston in the upper position an in the lower position.

Figure 2 is a slmilar section with the pistons reversed.

Figure 3 is a detail showing the means for operating the sparkplugs in the inner cylinder. p

. In the drawings I have shown my engine as it would be constructed wherein numeral 1 indicates the outer cylinder, numeral 2 the sleeve piston, numeral 3 the scavenging cylinder, numeral 4 the piston in the enlarged the inner piston gases in a cylinder formed piston of the outer cylinder and cylinder, numeral 5 the innerpiston, andnumeral 6rthe scavenging iston.

' The large or main cyllnder 1 may be constructed as shown with an intake valve 7, a

spark plug 8, and an exhaust port 9, an opening 10 which admits gas to the inner cylinder, and another opening 11 through which the gas from the inner cylinder may exhaust.

The inner sleeve piston 2 may be constructed as shown with an intake valve 12, a spark plug 13 and exhaust openings 14 through which the exploded gases may pass to the openings 11 in. the casing of the cylinder 1.

At the lower end of the cylinder 1 is the scavenging cylinder 3,, which has an intake opening 15 at one side of its upper. end, and a discharge opening 16 atthe other side.

The sleeve piston 4, in the cylinder 1, may I be constructed as shown with an opening 17 in its up er end, in which is the stem and spring 0 the valve 12. At..theupper end of thls opening is a plug 18 which may be removed when it is desired to adjust or replace the valve. Around the upper end of the cylinder are iston rings 19 which may be arranged as s own, or may b any desired points in the piston. In. this end of the piston is also an opening 20 which extends completely around it, thus separatin the head of the piston from the body, or

e placed at skirt, with the exception ofthe lugs 21which tie them together. It will be seen that as the opening .10 extends completely around the cylinder, gas may pass from it through the open ng er 2 when the pistons are in the In one side of the iston .4 and in the opening 20 is a lug 22, into which the spark p ug 13, maybe screwed, and at this oint 1s a lar opening 23 for the head 0 the sparkp ug, and a recess 24 for theoperating means as shown in Fi recess is a contact bar 25, w ich isinsulated from the piston'b the non-conducting material 26, and hel to it by a screw 27. The bar 25 engages a roller 28 on the end of a cylinder 29, which is slidabl moun ed in an opening 30 and constantly eld agginst the bar by a spring 31. The cylinder 2 is held in tube 32 and this is insulated from the cas-' ing of the main cylinder by the non-conducting material 33.; A cap 34 which also may 20 to the valve 12, which will'admit it-to cylind position shown in Figure 1.

re 3. In this m eel be placed on the outside casing" to hold the cylinder in place, and also to form a bearing for a stem 35 projecting from the cylinder. A contact wire may be attached to the outer end of the stem, and this may lead to a timelgor any suitable means for operating the sparkplug.

The piston 5 may be constructed in a manner similar to that of an ordinary iston, w1th a wrist pin 36 init by which it 18 connecte'd through the connecting rod 37, to the P in them for keeping them cool,

ofiset section 3d, of vthe crankshaft 39.

The scavenging piston 6 may be placed on the lower end of the piston 4, and may have two-connecting rods, 41 and 42, connecting it and the piston 4, through the wrist pins 43 and 44,-10' the ofiset sections l5 and 46 of the crankshaft 39. lt will be seen that the force of the explosion will be transmitted from the cylinder 1. through the connecting rodsdl and 4'2 to the cranksliatt. I

it is understood that the cylinder -1 may bemadeol any desired design and both'it and the piston 4 may have water jackets 47 The valves for admitting gases to and from the cylinders and also for admitting air to and from the scavenging cylinder may be di any suitable design, and maybe operated in any desired manner. The spark plugs and the means "for operating them may also he of any desired design,

it is understood that other changes may be made in the-construction without depart ing from the spirit of the invention.' @ne oil which changes may be in the length of the stroke, another may be in the design or size of the pistons or cylinders, and still another may be in the use of more of the units shown on the same crankshaft.

Then when they arrive at the position shown in Figure 2, the gas in the inner cylinder 2 will be exploded and this will force piston 5 downward and pistons 4 and 6 upward, and the connecting rodsfrorn both the pistons will transmit the power to the crankshaft. The .air in the scavenger cylinder will he forced throu h the" discharge port 1 l6 and into a tank connected by any suitable means to the inorn where it may he take valves oi?- the explosion chambers.

what I claim as new and desire to secure by Letters Patent is:-

1. A two-cycle engine having a piston within a sleeve piston, an outer cylinder, an enlarged cylinder, an enlarged piston depending from said sleeve piston, connections between said pistons to crankshaft, intake valves to said outer cylinder and to said sleeve piston, an annular row of intake ports on said sleeve piston and leading to its inlet valve, exhaust ports in said cylinder and sleeve piston, an explosivechamber within the outer cylinder and also within said sleeve piston and above said inner piston,

2. in a two cycle engine, having a piston within a sleeve piston, an outer cylinder, an

enlarged cylinder, an enlarged piston depending from said sleeve piston, connections between said pistons to a crank shaft, intake valves to said outer cylinder cnd to said sleeve piston, intake ports on said sleeve piston and leading to its inlet valve, exhaust ports in said cylinder and sleeve piston, an explosive chamber within the outer cylinder, and another explosive chamber within the said sleeve piston and above the said inner piston.

WILLIAM E. ElVAlt'l. 

